client: Add crio client package

Signed-off-by: Mrunal Patel <mrunalp@gmail.com>

client/client.go

@@ -0,0 +1,103 @@
+package client
+
+import (
+	"encoding/json"
+	"fmt"
+	"net"
+	"net/http"
+	"syscall"
+	"time"
+
+	"github.com/kubernetes-incubator/cri-o/types"
+)
+
+const (
+	maxUnixSocketPathSize = len(syscall.RawSockaddrUnix{}.Path)
+)
+
+// CrioClient is an interface to get information from crio daemon endpoint.
+type CrioClient interface {
+	DaemonInfo() (types.CrioInfo, error)
+	ContainerInfo(string) (*types.ContainerInfo, error)
+}
+
+type crioClientImpl struct {
+	client         *http.Client
+	crioSocketPath string
+}
+
+func configureUnixTransport(tr *http.Transport, proto, addr string) error {
+	if len(addr) > maxUnixSocketPathSize {
+		return fmt.Errorf("Unix socket path %q is too long", addr)
+	}
+	// No need for compression in local communications.
+	tr.DisableCompression = true
+	tr.Dial = func(_, _ string) (net.Conn, error) {
+		return net.DialTimeout(proto, addr, 32*time.Second)
+	}
+	return nil
+}
+
+// New returns a crio client
+func New(crioSocketPath string) (CrioClient, error) {
+	tr := new(http.Transport)
+	configureUnixTransport(tr, "unix", crioSocketPath)
+	c := &http.Client{
+		Transport: tr,
+	}
+	return &crioClientImpl{
+		client:         c,
+		crioSocketPath: crioSocketPath,
+	}, nil
+}
+
+func (c *crioClientImpl) getRequest(path string) (*http.Request, error) {
+	req, err := http.NewRequest("GET", path, nil)
+	if err != nil {
+		return nil, err
+	}
+	// For local communications over a unix socket, it doesn't matter what
+	// the host is. We just need a valid and meaningful host name.
+	req.Host = "crio"
+	req.URL.Host = c.crioSocketPath
+	req.URL.Scheme = "http"
+	return req, nil
+}
+
+// DaemonInfo return cri-o daemon info from the cri-o
+// info endpoint.
+func (c *crioClientImpl) DaemonInfo() (types.CrioInfo, error) {
+	info := types.CrioInfo{}
+	req, err := c.getRequest("/info")
+	if err != nil {
+		return info, err
+	}
+	resp, err := c.client.Do(req)
+	if err != nil {
+		return info, err
+	}
+	defer resp.Body.Close()
+	if err := json.NewDecoder(resp.Body).Decode(&info); err != nil {
+		return info, err
+	}
+	return info, nil
+}
+
+// ContainerInfo returns container info by querying
+// the cri-o container endpoint.
+func (c *crioClientImpl) ContainerInfo(id string) (*types.ContainerInfo, error) {
+	req, err := c.getRequest("/containers/" + id)
+	if err != nil {
+		return nil, err
+	}
+	resp, err := c.client.Do(req)
+	if err != nil {
+		return nil, err
+	}
+	defer resp.Body.Close()
+	cInfo := types.ContainerInfo{}
+	if err := json.NewDecoder(resp.Body).Decode(&cInfo); err != nil {
+		return nil, err
+	}
+	return &cInfo, nil
+}

cmd/crioctl/container.go

@@ -1,6 +1,7 @@
 package main
 
 import (
+	"encoding/json"
 	"fmt"
 	"log"
 	"net/url"
@@ -8,6 +9,7 @@ import (
 	"strings"
 	"time"
 
+	"github.com/kubernetes-incubator/cri-o/client"
 	"github.com/urfave/cli"
 	"golang.org/x/net/context"
 	remocommandconsts "k8s.io/apimachinery/pkg/util/remotecommand"
@@ -21,6 +23,7 @@ var containerCommand = cli.Command{
 	Aliases: []string{"ctr"},
 	Subcommands: []cli.Command{
 		createContainerCommand,
+		inspectContainerCommand,
 		startContainerCommand,
 		stopContainerCommand,
 		removeContainerCommand,
@@ -617,3 +620,37 @@ func ListContainers(client pb.RuntimeServiceClient, opts listOptions) error {
 	}
 	return nil
 }
+
+var inspectContainerCommand = cli.Command{
+	Name:  "inspect",
+	Usage: "get container info from crio daemon",
+	Flags: []cli.Flag{
+		cli.StringFlag{
+			Name:  "id",
+			Value: "",
+			Usage: "id of the container",
+		},
+	},
+	Action: func(context *cli.Context) error {
+		ID := context.String("id")
+		if ID == "" {
+			return fmt.Errorf("ID cannot be empty")
+		}
+		c, err := client.New(context.GlobalString("connect"))
+		if err != nil {
+			return err
+		}
+
+		cInfo, err := c.ContainerInfo(ID)
+		if err != nil {
+			return err
+		}
+
+		jsonBytes, err := json.MarshalIndent(cInfo, "", "    ")
+		if err != nil {
+			return err
+		}
+		fmt.Println(string(jsonBytes))
+		return nil
+	},
+}

cmd/crioctl/info.go

@@ -0,0 +1,31 @@
+package main
+
+import (
+	"encoding/json"
+	"fmt"
+
+	"github.com/kubernetes-incubator/cri-o/client"
+	"github.com/urfave/cli"
+)
+
+var infoCommand = cli.Command{
+	Name:  "info",
+	Usage: "get crio daemon info",
+	Action: func(context *cli.Context) error {
+		c, err := client.New(context.GlobalString("connect"))
+		if err != nil {
+			return err
+		}
+		di, err := c.DaemonInfo()
+		if err != nil {
+			return err
+		}
+
+		jsonBytes, err := json.MarshalIndent(di, "", "    ")
+		if err != nil {
+			return err
+		}
+		fmt.Println(string(jsonBytes))
+		return nil
+	},
+}

cmd/crioctl/main.go

@@ -91,6 +91,7 @@ func main() {
 		containerCommand,
 		runtimeVersionCommand,
 		imageCommand,
+		infoCommand,
 	}
 
 	app.Flags = []cli.Flag{

server/inspect.go

@@ -9,32 +9,12 @@ import (
 	"github.com/go-zoo/bone"
 	"github.com/kubernetes-incubator/cri-o/libkpod/sandbox"
 	"github.com/kubernetes-incubator/cri-o/oci"
+	"github.com/kubernetes-incubator/cri-o/types"
 	"github.com/sirupsen/logrus"
 )
 
-// ContainerInfo stores information about containers
-type ContainerInfo struct {
-	Name        string            `json:"name"`
-	Pid         int               `json:"pid"`
-	Image       string            `json:"image"`
-	CreatedTime int64             `json:"created_time"`
-	Labels      map[string]string `json:"labels"`
-	Annotations map[string]string `json:"annotations"`
-	LogPath     string            `json:"log_path"`
-	Root        string            `json:"root"`
-	Sandbox     string            `json:"sandbox"`
-	IP          string            `json:"ip_address"`
-}
-
-// CrioInfo stores information about the crio daemon
-type CrioInfo struct {
-	StorageDriver string `json:"storage_driver"`
-	StorageRoot   string `json:"storage_root"`
-	CgroupDriver  string `json:"cgroup_driver"`
-}
-
-func (s *Server) getInfo() CrioInfo {
-	return CrioInfo{
+func (s *Server) getInfo() types.CrioInfo {
+	return types.CrioInfo{
 		StorageDriver: s.config.Config.Storage,
 		StorageRoot:   s.config.Config.Root,
 		CgroupDriver:  s.config.Config.CgroupManager,
@@ -47,25 +27,25 @@ var (
 	errSandboxNotFound = errors.New("sandbox for container not found")
 )
 
-func (s *Server) getContainerInfo(id string, getContainerFunc func(id string) *oci.Container, getInfraContainerFunc func(id string) *oci.Container, getSandboxFunc func(id string) *sandbox.Sandbox) (ContainerInfo, error) {
+func (s *Server) getContainerInfo(id string, getContainerFunc func(id string) *oci.Container, getInfraContainerFunc func(id string) *oci.Container, getSandboxFunc func(id string) *sandbox.Sandbox) (types.ContainerInfo, error) {
 	ctr := getContainerFunc(id)
 	if ctr == nil {
 		ctr = getInfraContainerFunc(id)
 		if ctr == nil {
-			return ContainerInfo{}, errCtrNotFound
+			return types.ContainerInfo{}, errCtrNotFound
 		}
 	}
 	// TODO(mrunalp): should we call UpdateStatus()?
 	ctrState := ctr.State()
 	if ctrState == nil {
-		return ContainerInfo{}, errCtrStateNil
+		return types.ContainerInfo{}, errCtrStateNil
 	}
 	sb := getSandboxFunc(ctr.Sandbox())
 	if sb == nil {
 		logrus.Debugf("can't find sandbox %s for container %s", ctr.Sandbox(), id)
-		return ContainerInfo{}, errSandboxNotFound
+		return types.ContainerInfo{}, errSandboxNotFound
 	}
-	return ContainerInfo{
+	return types.ContainerInfo{
 		Name:        ctr.Name(),
 		Pid:         ctrState.Pid,
 		Image:       ctr.Image(),

types/types.go

@@ -0,0 +1,22 @@
+package types
+
+// ContainerInfo stores information about containers
+type ContainerInfo struct {
+	Name        string            `json:"name"`
+	Pid         int               `json:"pid"`
+	Image       string            `json:"image"`
+	CreatedTime int64             `json:"created_time"`
+	Labels      map[string]string `json:"labels"`
+	Annotations map[string]string `json:"annotations"`
+	LogPath     string            `json:"log_path"`
+	Root        string            `json:"root"`
+	Sandbox     string            `json:"sandbox"`
+	IP          string            `json:"ip_address"`
+}
+
+// CrioInfo stores information about the crio daemon
+type CrioInfo struct {
+	StorageDriver string `json:"storage_driver"`
+	StorageRoot   string `json:"storage_root"`
+	CgroupDriver  string `json:"cgroup_driver"`
+}